Improvement in processes of dyeing fabrics



PATENT QFFIGE.

ALEXANDRE SCHULTZ, OF PARIS, FRANCE.

IMPROVEMENT lN-PROCESSES OF DV'EING FABRICS.

Specification forming part of Letters Patent No. 170,307, dated November23, 1875; application filed September 10, 1875.

To all whom it may concern Be it known that I, ALEXANDRE SCHULTZ, ofParis, in the Republic of France, have invented improvements inoperating'with indigo in the printing of cotton and other fabricsproduced from vegetable fibers, of which the following is aspecification:

The invention relates to fixing the coloring matter, when employingindigo in printing on cotton and other fabrics produced from vegetablefibers, by a steaming process; and consists in the use of indigo-whiteand oxide of tin.

1n carrying out the invention the indigo is reduced to indigo-whitepaste by any of the known processes. This indigo-white paste is thenmixed with oxide of tin and a solution of gum-senegal or other suitablegum, in pro portions depending upon the percentage of pure indigocontained in the indigowhite paste. 7

The following proportions answer well, viz: For ten parts of pure indigocontained in the paste add one part of oxide of tin and solution of gumabout equal in quantity to the indigo-white paste, but varying with theshade of blue required.

These proportions may, however, be varied, and salts of tin and analkali which produces oxide of tin in the process may be used, takingcare that the color contains no free acid or alkali.

The oxide of tin used is, by preference, that obtained by precipitatingtin crystals with soda, in the usual manner.

The indigo-white paste used in carrying out this invention is thatobtained by precipitating a solution ofdeoxidized indigo in alkali by anacid and filtration; but it may be otherwise obtained.

In some cases, if desired, the indigo-white, in solution in alkali, maybe precipitated by an acid solution of tin crystals.

The coloring matter thus obtained is printed alone or in combinationwith other steam coloring matter, and the fabric is steamed for a periodwhich may vary from, say, half an hour to two hours, depending upon thecharacter of the other colors with which the in digo may be associatedin the printing.

After steaming, the fabric is washed and treated as may be necessary tothe more complete development of other colors with which this printingwith the indigo is asso ciated.

By such means the indigo-white or reduced indigo which is printed on thetissue combines with the cotton, and, by the steaming, is fixed on thefabric.

The indigo is fixed on the fabric by steam used in like manner to thatadopted in fixing alizarine and other steam-colors, so that, in thusprinting with indigo, other steam-colors may be readily associated withit, and the coloring matter thus obtained may be employed in combinationwith other coloring matters,

for producing various effects desiredas, for instance, by employingoxide-of lead, oxide of zinc, or oxide of baryta in combination with thecoloring matter above described, and passing the fabric to which thecombination has been applied through bichromate of potash aftersteaming, a fast green color will be obtained, varying in character withthe oxide employed, as well as by the character of the steaming and theproportions of the respective ingredients.

Having thus described my invention, I would have it understood that whatI claim 1s The within-described process of dyeing vegetable fiber, whichprocess consists, first, in

treating the fabric with indigo-white and ox-v ide of tin, in theproportions substantially as named, and then subjecting the so-treatedfabric to the action of live steam.

In testimony whereof I have signed my name to this specification in thepresence of two subscribing witnesses.

ALEXDRE SCHULTZ.

